It is known in the prior art to download information into a wireless telephone subscriber set or radio modem through the air interface from a central site, as evidenced by U.S. Pat. No. 5,297,191, "Method and Apparatus for Remotely Programming a Wireless Telephone Set" by I. Gerszberg, and by U.S. Pat. No. 5,418,524, "Method and Apparatus for Over-the-Air Upgrading of Radio Modem Application Software", by R. D. Fennell.
In this latter U.S. patent a selective call receiver includes a processor and a memory. The processor receives upgrade data and upgrade installation software, upgrades the modem's application software using the upgrade data, and then deletes the upgrade installation software and upgrade data.
It can be appreciated that the ability to update the software of a mobile terminal using the air interface is a significant advantage to both network subscribers and network providers, as the update can be accomplished without requiring the subscriber to return the terminal to a dealer or service center. Using the air interface to upgrade the terminal's software enables the service provider to download new and enhanced value-added features to requesting mobile terminals, and/or to update all subscriber terminals to take advantage of revisions to the applicable air interface standard. An air interface standard can be considered to be a set of rules or protocols which must be followed to successfully operate the mobile terminal in a given network over the air (i.e., wireless radio) interface. The standard known as IS-136.1 is one such air interface standard.
It can then further be appreciated that it is important to provide an efficient and accurate technique to upgrade the operating program of a mobile terminal over the air interface so as to cause a minimum impact on the availability of the mobile terminal to the user.